1. Technological Field
The present invention relates generally to fluid system components. More particularly, embodiments of the present invention relate to coupling elements for fluid system components, in which the coupling elements facilitate quick and efficient coupling/decoupling of the fluid system components. Further, embodiments of the present by invention relate to fluid system components which substantially prevent unintentional removal of a coupling element until the fluid system line pressure, or relative pressure differential, is reduced to a safe level.
2. Related Technology
In recent years, environmental concerns have been receiving significantly more attention, and various governmental agencies have responded by implementing stringent regulations to reduce or prevent pollution. Many of these regulations and concerns are directed towards those industries that transport fluids. For example, it is very difficult to transport a fluid without spilling or leaking some of the fluid into the environment. Thus, some environmental regulations require that only minimal leakage occur during handling, processing, or transportation of the fluid.
These environmental concerns become especially clear when considering the magnitude of the industries that handle hazardous fluids that, if allowed to escape even in relatively small quantities, can cause significant damage. There is a concern, therefore, to protect both the public and the environment from these types of fluids. While some fluids that are transported, such as water and milk, may not significantly pollute the environment when they are leaked or spilled, the loss of fluid into the environment is nevertheless viewed as a general waste of resources. More generally, the loss of fluid into the environment is not desirable even if the fluid does not contribute to pollution.
Within the transportation industry, a variety of different devices are used to transport a fluid from a source to a destination. These devices often use valve assemblies and conduits of various types to both connect the source to the destination as well as to manage fluid flow through the conduit. Typically, the conduit is pressurized to direct fluid toward the desired destination. With each transfer of fluid, there is a risk that leakage will occur due to human error, equipment malfunctions, or the like.
A common source of fluid leaks and fluid spills are the valves and other components and devices employed in fluid systems. By way of example, some valves may have leaks that permit flow through the valve even when the valve is secured in the closed position. In other instances, one or more joints defined by constituent elements of the valve, such as in the case of valves designed to be taken down in two or more pieces, and/or one or more joints at least partially defined by the valve, such as a valve-to-flange connection, may be defective, resulting in leakage of some or all of the system fluid. Unfortunately, problems such as these often do not manifest themselves until after flow has been established through the valve, component, or device.
Thus, in many instances, the system operator is limited in terms of the affirmative steps that can be taken to prevent a spill that may result from one or more defective joints, and oftentimes can only correct the spill when it occurs. This is true in the case of joints that are defectively assembled, or are otherwise defective upon assembly, as well as in the case of joints that become defective over a period of time due to operating, or other, conditions.
Other problems exist as well. For example, various types of valves have been designed to stop, or “check,” fluid flow through the valve when the valve is taken down into two or more constituent parts or assemblies. One known device for checking fluid flow is a ball check valve. A ball check valve is essentially a ball which rests against a ball seat to form a valve. An operator may use the ball check valve to initiate or terminate the fluid flow. Despite the check feature of the ball check valve, a problem exists in the integrity of the fluid transfer system when the valve or conduit undergoes stress.
When the conduit and the valve are subjected to forces such as stretching, pulling, twisting, and the like, the fluid being transferred through the conduit and the valve may leak or spill into the environment. More particularly, the conduit, rather than the ball check valve, is likely to rupture or otherwise malfunction in the presence of these forces. Thus, while the ball check valve is appropriate for checking fluid flow, it does not prevent spillage or leakage when subjected to external stress. Because the conduit is likely to rupture, or otherwise malfunction, in these types of situations, the spillage or leakage of fluid into the environment can be significant because the fluid flow can no longer be checked.
For example, when a fuel transport vehicle is delivering liquid through a hose into a fuel tank, one end of the hose is attached to the fuel transport vehicle, and the other end of the hose is attached to a fuel tank. A valve such as a ball check valve may be disposed at the vehicle end of the hose such that fluid communication through the hose may be established or checked.
In the event the fuel transport vehicle drives away with the hose still connected, the connection will likely break or rupture. Because the hose is typically the weakest part of the connection, the break usually occurs somewhere in the hose and fluid escapes into the environment. In this example, the ball check valve typically does not disassemble because it is much stronger than the hose. Even if the ball check valve were to break instead of the hose, fluid would still leak from the system. Such problems are particularly acute in the context of automated environments and operations where few, or no, humans may be present, and a leak may go unnoticed for a relatively long period of time.
Another concern relates to the coupling and uncoupling of caps, valves, and other fluid system components that are employed, for example, in fuel, chemical, sewage, or other fluid transfer or processing systems. In particular, typical quick coupling devices are configured so that an operator can uncouple the mating halves of the quick coupling device, even in the presence of line pressure. Such an arrangement is problematic for a variety of reasons.
By way of example, in the event the line wherein the quick coupling device is located is charged with hazardous materials such as chemicals, sewage, fuels, or gases such as chlorine and methane, the operator performing the uncoupling operation could be seriously injured or killed when such materials escape from the line. Moreover, such hazardous materials are pollutants and significant time and cost is often involved in the cleanup of such materials.
A related problem with typical quick coupling devices concerns the pressure exerted by the material in the line wherein the quick coupling device is located. In particular, such pressure may cause the halves of the quick coupling device to rapidly come apart in an uncontrolled and dangerous manner, thereby injuring the operator and/or damaging nearby equipment. The forces resulting from such pressure can often be significant, even where the line pressure is relatively low. Thus, in a six inch diameter (nominal) pipe for example, even a relatively low pressure of ten (10) lbs./in.2 (“psi”) would exert a force of about one thousand (1000) pounds on a pipe cap attached to the end of the pipe.
Not only are such pressures dangerous, but operators may not have any way to verify, in advance of performing the uncoupling operation, whether or not the line is pressurized. Further, even if an operator is aware that pressure is present, the operator may, through inattentiveness, negligence, or for other reasons, nevertheless attempt to uncouple the quick coupling device.
In view of the foregoing, what is needed is a fluid system component having features directed to addressing the foregoing exemplary considerations, as well as other considerations not disclosed herein. More particularly, an exemplary fluid system component includes features directed to facilitating the secure engagement, and ready disengagement, of the mating halves of the fluid system component, while at the same time preventing intentional or accidental disengagement of the mating halves when a predetermined pressure is present in the line.